The present invention relates generally to signal lights, and more particularly to signal lights with increased visibility that are suitable for use as traffic signal lights, e.g., on roads or railways.
A type of traffic signal light utilized heretofore is illustrated in FIG. 1. Such lights generally comprise a lamp 10, a transparent colored cover 12, a casing 14, and a hood 16. Signal lights with red and green, or red, yellow and green transparent colored plates 12 are utilized in combination, and traffic signals are given by lighting one or the other of the signal lights.
However, when direct sunlight strikes a traffic signal light, an extinguished signal light is difficult to distinguish from a lit signal light. As a result, there is a danger of accident due to misreading of the signals.
It is possible to increase the brightness of lamp 10 in order to improve the visual distinguishability of the signal light. However there are limits to the effectiveness of this technique under direct sunlight.
The present invention eliminates the above-mentioned drawback of signal lights, and provides a signal light which can easily be visually distinguished even under direct sunlight conditions.
An object of the present invention is to provide a signal light that produces a signal that is easily, visually distinguishable under direct sunlight conditions.
A further object of the present invention is to provide a signal light that protects the liquid crystal material from ultraviolet light.
Another object of the present invention is to provide a signal light that reduces glare otherwise present thereon.